Earth-boring drill



Nov; 20, 1928.

C. E. REED EARTH BORING DRILL Filed Feb. 27, 1928 E A n J H $4 PATENT OFFICE.

cnanngwn a. se, or wrcnrrn, KANSAS.

EARTH-BORING DRILL.

REISSUED.

Application filed February 27, 1928. Serial No. 257,259.

Myinvention is an improvement in the type of earth boring ent of the Unlted States granted to me, for instance, Nos. 1,636,665-6-7, July 19, 1927,

5 and concerns means for holding a rotary conical cutter on its spindle.

The invention consists in the features and combination and arrangementof parts hereinafter described and particularly pointed 1 out in the claims. In the accompanying drawings: Figure 1 is a view of the roller cutter unit with parts in section and parts in elevat on, and with a part of the head shown in section. Fig. 2 is a sectional view of the threaded l ig. 3 is a sectional view of one of the looking segments.

Fig. 4 is a face view of the locking segments. Fig. 5 is a face view of the threaded rmg. In this drawing 1 indicates a part of the bit head. The roller cutter unit has a shank 2 to fit removably in a socket 3' of this head, where it is held by any suitable locking mem- 25 her such as indicated generally at 4. This may be of the form disclosed in Letters Patent of the United States granted to me.

The shank 2 extends at an angle from the base plate 5 of the unit, which base plate is adapted to fit a seat recess in the bit head.

From this base plate a spindle 6 pro]ects and on this spindle the roller cutter 7 is revolubly mounted. The spindle may be of stepped form, presenting portions of different diameters as shown, or it may be of other forms, such for instance as conical.

The roller cutter which is conical or approximately so has a bore to fit in part the shape of the spindle. For locking the roller cutter on thespindle in such manner that it will be retained in proper position relative to the bit head and yet be capable of free rotative movement about the spindle, I provide floating segments 8, 8 mounted in a groove 9 of the spindle, and of such external diameter as to project from said spindle and thus provide, 1n effect, an annular rib or shoulder. The portion of the bore in the roller cutter adj acent this ring or shoulder made up of the seg- $0 ments is formed to fit said ring. At the large or rear end of the bore of the roller cutter a ring 10 is mounted, this being connected with the cutter member by a screwthread, so that the said ring turns with the roller. The

ll inner diameter of the screw ring 10 is such that it will turn freely on the spindle, and at the drills shown in Letters Patfront side, i. e., at 11, theface of the ring contacts with the rear or inner face of the segmental locking ring 8, 8. By the engagement of the screw ring back of the segmental ring, the roller cutter is retained on the spindle, but with freedom of rotation thereon. The screw ring has sockets at 12 by which a holding implement may be engaged with the ring to hold it while the roller cutter is turned to screw it onto the ring. When these parts, roller and screw threaded ring, have been assembled, they may be held by a pin 13 passing through the wall of the roller cutter into a socket 14 of the ring.

In assembling the parts of the roller cutter unit, this is done outside thebit head by first placing the screw ring on the spindle, thereafter placing the segments 8, 8 of the locking ring in position in the groove of the spindle, then screwing the roller cutter onto the screw threaded ring, and then, desirably, fixing the screw ring and roller cutter together by inserting the pin before mentioned.

The primary purpose of the segmental ring 8, 8 is to lockthe cutter in place by providing a shoulder at its rear side againstwhich the screw threaded ring will find a retaining hearing, it being understood that this screw ring when seated in the bore of the roller cutter virtually forms a part of said roller. The segmental ring is adapted to turn or float with the roller and thus has an anti-friction character or quality. In the event that lubricant is introduced into the bore of the roller, this ring will form a seal against its escape.

One way that the roller cutter may be lubricated is to lead oil through a conduit in the spindle, to the fore part of the bore of the roller cutter, so that this will find its way between the exterior of the spindle and the roller. The ring will prevent undue escape of this lubricant. It also resists back pressure in the well and keeps sand out of the bearing.

It further resists the inward thrust from the side of the bore hole on the cone, and it carries part of the working load from the normal operating surface of the cone. ing ring enables a one piece screw threaded ring to be used.

The assembly can be quickly made. The screw threaded ring being in one piece can be handled as one body, and as no accurate registration of parts, such as in the case of a divided screw threaded ring, is necessary, the screwing on of the cone can be performed with certainty and with ease. The spindle,

This split lock- 7 together with its base plate and shank, are all formed in one ieoe'.

, The split loc 'ng ring can be quickly assembled by placing its sections separately into po- 6 sition from opposite sides of the spindle into the ove formed therein. T e unit consisting of the shank, base plate s indle and roller cutter mounted thereon as 0. ve described, is'intended to be handled as one body in connecting it up with the head or in removing it therefrom. a Y

It will be understood, however, that I do ot limit my present invention to its applica- 101'). above made is not to be regarded as a limitation upon my invention, the scope of which is defined by the appended claims.

Referring to the specific means for holding 'the shank of the roller cutter unit in place, this in the illustrated embodiment of my invention consists of a nut 4 screw threaded onto the shank of the spindle with the left hand screw-thread. There is a locking nut also screw threaded onto the shank at 4 and there is a washer at 4. The lock nut may be held on by a suitable cotter pin if desired. By reason of this arrangement, contact of the nut with the material at the side of the hole being drilled, will tend to tighten the nut instead of loosening it, this result being due to the directo this removable unit and the disclosure asagna manner of attaching this ring to the roller. v

cutter. a v

I claim: v 1. A roller cutter unit for earth borin drills comprising a spindleand shank, sai a) spindle havin anvannular groove in its surface, a ring of one piece mounted to turn on said spindle, segmental pieces seated in the annular groove, and furnishing a retaining bearing for and engaging the front faceof the ring, and a roller cutter mounted on the spin 7 dle and to which the ring is attached, said roller cutter having a bore adaptin it to slip axially along the spindle over the segmental pieces to the, ring for attachment thereto substantially described.

2. An earth boring drill according to claim 1 in which the segmental pieces are unattached to the roller cutter and are adapted to float in the annular groove of the spindle by 55 the frictional contact of the ring and cutter therewith.

In testimony whereof, I aflix my signature.

CLARENCE E. REED. 

